Drive couplings

ABSTRACT

A coupling for use in a fuel injection pump comprises a pair of members and a fluid pressure operable piston acting intermediate the members. The supply of fluid under pressure of the pistons is controlled by a valve member which is disposed to be influenced by centrifugal force. The motion of the valve member under the action of centrifugal force is resisted by a leaf spring and the force exerted by the leaf spring is adjustable by means of a roller which co-operates with a surface on a member in such a manner that as the centrifugal force increases and the piston moves to effect relative movement of the members, the roller will move to increase the force exerted on the valve element thereby to establish an equilibrium.

I United States Patent 1191 [111 3,774,41 1

Phillips et al. Nov. 27, 1973 DRIVE COUPLINGS 3,062,027 11 1962Pigeroulet 64/25 3,258,937 7/1966 K t l. 64 25 75 Inventors: RonaldPllllllps, 1901 11611; Zdznslav 2,950,610 8/1960 n Stamsh" Mlraekl,Fmehley, 3,603,112 9 1971 S0l3.... 64/25 London, both of England [73]Assignee: Simms Group Research & 1 P'imary Examinerchal'les yDevelopment Limited, mndon Assistant En land Attorney-Holman and Stern22 Pl d: Se 1. 23 1971 1 p 57 ABSTRACT [21] Appl 183056 A coupling foruse in a fuel injection pump comprises a pair of members and a fluidpressure operable piston [30] Foreign A li ation Pri it D t actingintermediate the members. The supply of fluid Sept. 30 1970 GreatBritain 46 409 70 Pressure of the Pistorls is controlled by a valvemember which is disposed to be influenced by centrif- 52 us. Cl. 64/25,123/139 AP feree- The ef the valve member under the 51 lm. Cl. Fl6daetie" ef centrifuge feree is resisted by a leaf Spring [58] Field ofSearch 64/25 26- end the force exerted by the leaf spring is adjustable123/139 by means of a roller which co-operates with a surface on amember in such a manner that as the centrifugal [56] References Citedforce increases and the piston moves to effect relative movement of themembers, the roller will move to in- UNITED T T PATENTS crease the forceexerted on the valve element thereby 31%? s i to establish anequilibrium, 9 1 Z aga 6 Claims, 6 Drawing Figures 3,004,410 10/1961Pierce 64/25 El o PATENTEDHUYZT E975 3774.411 sum 2 a? 4 FIGS.

INVENTOR ATTORNEYS DRIVE COUPLINGS This invention relates to drivecouplings for use with liquid fuel injection pumping apparatus having adrive shaft, the coupling comprising in combination, a pair of membersone of which is connected to the drive shaft and the other of which isconnected in use, to a rotary drive element, means coupling the membersto transmit rotary motion therebetween and means for varying therelative angular position of said members.

The object of the invention is to provide such a coupling in a simpleand convenient form;

According to the invention a coupling of the kind specified comprises abore defined in one of the members, a fluid pressure operable pistonmounted in said bore and arranged when subjected to fluid pressure toeffect relative angular movement of the members, resilient means actingbetween said members and against the action of which the members aremoved angularly by the piston, valve means including a valve elementwhich is movable under. the action of centrifugal force for controllingthe admission of fluid under pressure to said bore, spring means actingon said valve element to oppose the action of centrifugal force andmeans responsive to the relative angular position of the members'forvarying the force exerted by the spring means on the valve element.

One example of a drive coupling in accordance with the invention willnow be described with reference to the accompanying drawings in which:

FIG. 1 is a section on the line AA of FIG. 5,

FIG. 2 is a section on the line B-B of FIG. 1,

FIG. 3 is a section on the line D-D of FIG. 1,

FIG.,4 isasection on the line C--C of FIG. ll,

FIG. 5 isa side elevation of the coupling with part of thecover removedto show the interior of the coupling,

and

FIG. 6 is a partial view similar to FIG. 1 showing an alternativeposition of the parts of the coupling.

Referring to FIG. 2 the coupling comprises a pair of members 10, 11 themember 11 being joumalled about a cylindrical extension formedintegrally with the member 10. The member 10 is provided with a taperedbore 1 12 in which is engaged a drive shaft 13 forming part of a liquidfuel pumping apparatus, the housing of which is seen at 14. The member10 is accommodated within a cup shaped housing 15 the open end of whichextends around the member 11. Moreover, located in the member II is aperipheral groove in which is accommodated a fluid seal 16.

Turning now to FIG. 11 it will be seen that the member 10 is cut away atsubstantially diametrically opposite points to accommodate projectionsIlla formed on the member 11. The member 10 defines a pair of blindbores 17 which extend in opposite directions and located within the bore17 are a pair of pistons 18 respecmunicate with a drain passage 26 asupply passage 27 respectively. The supply passage 27 communicates witha passage 28 formed within the pump casing 14 and this communicates witha source of fluid under pressure.

The extent of inward movement of the valve element 23 is limited by apin 29 and at its outer end the valve element bears against a springmeans in the form of a leaf spring 30. At one end the spring 30 isengaged around a post 31 connected to the member 10 and adjacent itsother end the spring 30 bears against a roller 32 carried upon a forkedarm 33 which is pivotally connected to the adjacent extension Ii la ofthe member 1 1. In addition, the roller 32 bears upon a shaped surfaceformed on an abutment member 34 which is carried by the member 10. Inaddition, resilient means in the form of a pair of springs 35 areprovided to urge the members l0 and 11 relative to each other againstthe action of the force developed by the pistons 18.

In operation, the coupling rotates in the anticlockwise direction asseen in FIG. 1, the member 11 being driven by the associated engine sothat the drive is transmitted through and the spherical members 19 andthe pistons 18 to the member 10. The valve element 24 being disposed ina radial plane, is subjected to centrifugal force and as the valveelement moves outwardly against the action of the spring 30 the port 21will be uncovered to the groove 25 so that fluid under pressure isadmitted to the cylinders 17. The effect of this is to urge the pistonsoutwardly from their cylinders and relative angular movement will occurbetween the members 10 and Ill. As such angular movement takes place theforked member 33 will move relative to the member 34 and the roller 32will be moved inwardly due to the-action of the shaped surface of themember 34. The effect of this inward movement of the roller is toslightly shorten the effective length of the spring 30 but also to bowthe spring so that it exerts an increased force on the valve element. Apoint is reached at which an equilibrium is established and the port 21is closed. Once the port 21 is closed as hydraulic lock exists in theends of the cylinders and no further movement of the pistons takesplace. If the speed increases further the process is repeated and if thespeed decreases the valve element 23 moves in the opposite directionunder the action of the leaf spring until the port 21 is uncovered tothe groove 24. When this occurs fluid escapes from the cylinders 17 anda fresh equilibrium is established.

As is shown in FIG. 3 the forked member 33 at its end remote from theroller 32, is pivotally mounted about a pin 36 and this pin iseccentrically mounted upon an angularly adjustable member 37. In thismanner the initial position of the roller 32 upon the shaped surface ofthe member 34', can be adjusted and in this manner the responsecharacteristic can be adjusted.

We claim:

1. A drive coupling for use with liquid fuel injection pumping apparatushaving a drive shaft, the coupling comprising in combination, a pair ofmembers one of which is connected in use, to a rotary drive element, abore defined in one of the members, a fluid pressure operable pistonmounted in said bore and arranged when subjected to fluid pressure toeffect relative angular movement of the members, resilient means actingbetween said members and against the action of which the members aremoved angularly by the piston, valve means including a valve elementwhich is movable under the action of centrifugal force for controllingthe admission of fluid under pressure to said bore, spring means actingon said valve element to oppose the action of centrifugal force andmeans responsive to the relative angular position of the members forvarying the force exerted by the spring means on the valve element.

2. A coupling as claimed in claim 1 in which said spring means comprisesa leaf spring, said valve element contacting the leaf springintermediate the ends thereof.

3. A coupling as claimed in claim 2 in which one end of the leaf springis secured to one of the members, and the other end of the leaf springbears against a roller the position of which varies as a result ofrelative angular movement between the members.

4. A coupling as claimed in claim 3 in which said roller is mounted onan arm carried by the other of said members.

5. A coupling as claimed in claim 4 including an abutment member carriedby said one member said abutment member defining a shaped surfacebetween which and the leaf spring is located the roller, said surfacebeing shaped so that as the piston moves under the action of increasingfluid pressure to effect relative movement of the members, the rollerwill move on the surface to increase the force applied by the spring tothe valve element.

6. A coupling as claimed in claim 5 including means for adjusting theinitial position of the roller on said surface.

1. A drive coupling for use with liquid fuel injection pumping apparatushaving a drive shaft, the coupling comprising in combination, a pair ofmembers one of which is connected in use, to a rotary drive element, abore defined in one of the members, a fluid pressure operable pistonmounted in said bore and aRranged when subjected to fluid pressure toeffect relative angular movement of the members, resilient means actingbetween said members and against the action of which the members aremoved angularly by the piston, valve means including a valve elementwhich is movable under the action of centrifugal force for controllingthe admission of fluid under pressure to said bore, spring means actingon said valve element to oppose the action of centrifugal force andmeans responsive to the relative angular position of the members forvarying the force exerted by the spring means on the valve element.
 2. Acoupling as claimed in claim 1 in which said spring means comprises aleaf spring, said valve element contacting the leaf spring intermediatethe ends thereof.
 3. A coupling as claimed in claim 2 in which one endof the leaf spring is secured to one of the members, and the other endof the leaf spring bears against a roller the position of which variesas a result of relative angular movement between the members.
 4. Acoupling as claimed in claim 3 in which said roller is mounted on an armcarried by the other of said members.
 5. A coupling as claimed in claim4 including an abutment member carried by said one member said abutmentmember defining a shaped surface between which and the leaf spring islocated the roller, said surface being shaped so that as the pistonmoves under the action of increasing fluid pressure to effect relativemovement of the members, the roller will move on the surface to increasethe force applied by the spring to the valve element.
 6. A coupling asclaimed in claim 5 including means for adjusting the initial position ofthe roller on said surface.